Lithoplate bender

ABSTRACT

A semiautomatic machine for simultaneously bending the leading and trailing edges of a lithographic printing plate. The plate bender has a ruggedly constructed frame which supports and guides a vertically movable plate supporting bed. The bed has a fixed anvil with a pair of spaced locating pins and an anvil which is movable relative to the fixed anvil to adapt the bender to bend different size printing plates. A fixed and movable pressure block are supported a short distance above the fixed and movable anvils, respectively. Each of the pressure blocks has a spring biased vertically movable gripping face and a cam operated horizontally movable forming block. An adapter is also provided to enable the bender to shape lithographic plates smaller than the adjustable range of the bender. In operation, a prepunched lithographic printing plate is positioned on the locating pins. The plate supporting bed is then driven vertically by a pneumatic cylinder to bring the plate and anvils into engagement with the pressure blocks. The bed continues to rise causing the pressure blocks to firmly grip the printing plate and to rise against the downward biasing force. As the pressure blocks move a camming slot at each end of the blocks acts upon a cam follower within the slot causing it to move in a horizontal direction relative to the pressure block. The cam followers draw the forming blocks inward toward the printing plate causing the leading and trailing edges of the plate to simultaneously bend inward against forming faces on the anvils. After the plate is bent the bed is lowered allowing the operator to slide the formed plate off of the anvils.

United States Patent Miller et al.

[54] LITHOPLATE BENDER [72] Inventors: Leo H. Miller, Penfield; James A.

Colegrove, Rochester, both of NY.

[73] Assignee: Burroughs Corporation, Detroit, Mich.

[22] Filed: Feb. 19, 1971 [21] Appl. No.: 116,975

[52] US. Cl ..72/403 [51] Int. Cl ..B2ld 5/01 [58] Field of Search......72/403, 452, 380, 381, 382,

[56] 7 References Cited UNITED STATES PATENTS 133,975. 12/1872 Foglesong..72/403 1,701,250 2/1929 Young ....72/382 1,706,273 3/1929 Woodin gs.......72/403 2,591,483 4/1952 West..... ..72/403 Primary Examiner-CharlesW. Lanham Assistant Examiner-Gene P. Crosby Attorney-Kenneth L. Millerand Kevin R. Petersonv 57 ABSTRACT A semiautomatic machine forsimultaneously bending the [151 3,677,059 [451 July 18, 1972 leading andtrailing edges of a lithographic printing plate. The plate bender has aruggedly constructed frame which supports and guides a verticallymovable plate supporting bed. The bed has a fixed anvil with a pair ofspaced locating pins and an anvil which is movable relative to the fixedanvil to adapt the bender to bend different size printing plates. Afixed and movable pressure block are supported a short distance abovethe fixed and movable anvils, respectively. Each of the pressure blockshas a spring biased vertically movable gripping face and a cam operated.horizontally movable forming block. I

An adapter is also provided to enable the bender to' shape lithographicplates smaller than the adjustable range of the bender.

In operation, a prepunched lithographic printing plate is positioned onthe locating pins. The plate supportingbed is then driven vertically. bya pneumatic cylinder to bring the plate and anvils into engagement withthe pressure blocks. The bed continues to rise causing the pressureblocks to firmly grip the printing plate and to rise against thedownward biasing force.

As the pressure blocks move a camming slot at each end of the blocksacts upon a cam follower within the slot causing it to move in ahorizontal direction relative to the pressure block. The cam followersdraw the forming blocks inward toward the printing plate causing theleading and trailing edges of the plate to simultaneously bend inwardagainst forming faces on the anvils. After the plate is bent the bed islowered allowing the operator to slide the formed plate 0E of theanvils.

18 Claims, 9 Drawing figures PATENTED JUL 1 81972 SHEET 1 [1F 4 IIIINVENTORS.

JAMES A. COLEGROVE BY & LEO H. MILLER 41 fi/ ATTORNEY PATENTEU JUL I 8I972 SHEET 2 0F 4 INVENTOR.

JAMES A. COLEGROVE & LEO H. MILLER/'1 fLL/X/ 1+ WF/ 5 .t v QM ATTORNEYPATENTEU JUL! 8 I972 SHEET 3 BF 4 m A L P INVENTORS. JAMES A. COLEGROVEBY & LEO H. MILLER PATENIEnmwm 3.677.059

SHEET u 0F 4 FIG. 6

I N VEN TOR.

JAMES A. COLEGROVE & LEO H. MILLER ATTORNEYv LITI-IOPLATE BENDERBACKGROUND OF THE INVENTION In lithographic printing, a photosensitiveplate of aluminum is exposed to a photographic image which causesportions of the photosensitive material to become solvent insoluble.Following exposure the plate is washed with a solvent to remove thesoluble portion and to prepare the printing image. The plate is thenready for mounting on the plate roll of a lithographic printing press.

The typical plate roll has a slot running across the roll into which theends of the lithoplate are placed. One edge of the slot, the leadingedge, is formed at an angle and provides an alignment edge for theprinting plate. The tail end of the slot has a radius to allow the plateto be smoothly drawn into the slot. An eccentric rod is mounted withinthe slot. The rod has a cutout the width and length of a printing platethrough which the tail edge of the plate is passed. The eccentric rodcan then be rotated to draw the lithoplate tightly about the press rolland to compress the leading edge of the plate against the inside of theslot.

It is essential to the operation of a lithographic press that the platesbe bent accurately in order to properly register the printing image onthe press roll. The sharp bend of the leading edge of the plate servesto align the plate on the press roll. If this bend is not accuratelymade the plate will not wrap evenly about the press roll and willproduce a crooked or blurred print. Blurring of the print will result ifthe plate cannot be wrapped tightly against the press roll and has abulge which is subject to deformation under printing pressure.

The tail portion of the printing plate must also be carefully bent toavoid a sharp crease which could project above the level of the plate.Even after tightening, the ridge fonned by the sharp edge would producean undesired line of print. The tail portion must be bent in arelatively smooth arc to allow the edge to fit into the slot on thepress roll and into the cutout in the eccentric rod to allow fortightening of the plate on the press roll.

In the past, it has been the usual practice to provide a tool forbending the edges of the printing plates adjacent to the press so thepress operator could bend the prepared plates for mounting on the pressroll. This is an undesirable procedure since it requires the pressoperator, who is highly paid, to leave the press to do the bending.Also, if the operator does not bend the plate accurately to maintainprecise registration of the image or if he does not bend the plateproperly it becomes useless for printing and all of the prior time andexpense in plate preparation is wasted.

The lithoplate bender of the present invention overcomes theaforementioned problems by making the bending of the plate asemiautomatic operation which can be carried out by an unskilledoperator in the plate preparation area. The operator merely has to placea prepunched plate on a pair of registration pins within the bender andthen actuate the machine. The bender precisely bends the lead and tailedges of the plate to the proper angle and through the use of the sameregistration holes used to place the image on the plate insures properregistration of the image with the alignment or leading edge of theplate.

BRIEF SUMMARY OF THE INVENTION The present invention relates to asemiautomatic bender for lithographic printing plates. The bender has asupporting frame which holds a vertically movable table which is drivenby a pneumatic ram. A pair of plate forming anvils are mounted on themovable table. One of the anvils has a relatively sharp plate formingsurface and a pair of spaced locating pins. The other anvil isadjustable relative to the fixed anvil for bending different sizeplates. The adjustable anvil has a radius on the bending edge forproducing a smooth curve.

Above the anvils and movably supported by the frame are a pair of springbiased pressure blocks. One of the pressure blocks is fixed relative tothe fixed anvil while the other pressure block is movable relative tothe adjustable anvil. The pressure blocks are provided with spacedcamming slots at the ends of the blocks. A movable forming block ismounted between the camming slots on each of the pressure blocks and hasa cam follower for moving the forming blocks in a horizontal directionwhen the pressure block is moved vertically. The table is adapted tomove, bringing the anvils into engagement with the pressure blocks.Further movement of the table causes the pressure blocks to move,camming the forming blocks into engagement with the forming surfaces onthe anvils.

In operation, a lithographic printing plate is placed on the anvils andhooked over the locating pins. The bender is then actuated causing thetable to rise bringing the plate into contact with the pressure blocks.As the table continues to rise the anvils and pressure blocks tightlygrip the plate and the camming track begins to draw the forming blocksinto engagement with the plate. The table, anvils, plate, and pressureblocks continue to rise and the forming blocks continue to be drawninwardly until the plate is fully bent. The operator then disengages themachine and the table lowers carrying the finished bent lithographicplate. The machine can also be adapted to automatically lower the tableafter the bend is completed by means of a limit switch. The plate can heslipped off the anvils by the operator and is ready for mounting on thepress roll of a lithographic press.

An adapter is also provided for mounting on the fixed anvil for bendingplates smaller than those for which the machine is adjustable. Theadapter has plate forming surfaces and locating pins to insure theproper bending of the plate.

BRIEF DESCRIPTION OF THE DRAWINGS The invention, both as to itsorganization and method of operation, together with further advantagesthereof, will best be understood by reference to the following detaileddescription taken in connection with the accompanying drawings, inwhich:

FIG. I is a front elevation view of the lithoplate bender of the presentinvention.

FIG. 2 is a side elevation view of the lithoplate bender.

FIG. 3 is a top plan view.

FIG. 4 is a sectional view taken in the direction of the line 44 of FIG.1.

FIGS. 5a, 5b, and 5c are schematic views illustrating the operation ofthe lithoplate bender.

FIG. 6 is a front elevation view of the bender showing the small plateadapter in place on the anvil of the bender.

FIG. 7 is a sectional view taken in the direction of the line 7-7 ofFIG. 6.

DETAILED DESCRIPTION Referring to FIGS. 1 and 2, the lithoplate benderis shown to have a box-like supporting frame made up of foursubstantially identical legs 11 which are preferably made of heavy angleiron. A heavy plate 13 is joined to the legs and forms a fixed tabletop. Four substantially identical posts 15 are fixed at each of thecorners of the table top 13. The posts 15 support a heavy metal topplate 17, completing the framework for the lithoplate bender. Each ofthe members forming the frame for the lithoplate bender are of heavymetal construction in order to preclude distortion of the bender whileshaping a printing plate. If the bender tended to distort while formingthe edges of a printing plate, it could result in poor registration ofthe ultimate print.

The lithoplate bender is designed to be adjustable so that it can handlemany different size printing plates. The usual lithographic plates rangefrom 14 inches X 20 inches up to 27 inches X 26 inches. The range ofprinting plates for which the bender was originally designed was 17inches X 20 inches to 22 inches X 32 inches. For this reason, the fixedtable top 13 was designed to have dimensions approximately 36 inches X4l inches X l inches. Obviously, the lithoplate bender can be scaled upor down in size to correspond to the range of lithoplates to be bent.While the usual lithographic printing plates come in many differentsizes, they are all approximately 0.009 inches thick. Since this is alittle more than the thickness of a sheet of paper, the substantialconstruction of the bender appears to be out of place. However, aspointed out above, the heavy construction insures the proper bending ofeach plate and in turn the proper registration of each print relative tothe leading edge of the plate and the locating pins.

The lithoplate bender has a movable bed 19 which is supported and guidedby the fixed table top 13. As shown in FIG. 1, the bed 19 is drivenvertically by a pneumatic ram 21 which has a drive shaft 23 journaledthrough the top 13. The pneumatic ram 21 is attached to and is supportedby the top 13. Near each end of the movable bed 19 is a depending guidepost 25 which is journaled through a ball bushing 27 in the table top13. The guide posts 25 are approximately six inches long by one inch indiameter and preclude any tilting or cocking of the movable bed 19 as itis driven by the pneumatic ram 21.

On the upper surface of the bed 19 are mounted a fixed anvil 29 and amovable anvil 31. The fixed anvil 29 has locating pins 32 and 34 whichare used to align the lithographic plate on the surface of the anvil.The pins 32 and 34 are substantially identical to the pins used inaligning the plate during the exposure and image-forming steps. By usingthe same locating hole in the plate and substantially identical locatingpins, proper registration of the image relative to the printing plate isassured in the bent plate. The anvil 29 is fixed on the movable bed 19and has a working face 33 which is used to form the sharp angle at theleading edge of the printing plate. The anvil 31 is adjustable relativeto the fixed anvil 29 and has a working face 35 which forms the tailedge of the printing plate. The face 35 should be formed with a radiusto provide for smooth tightening ofthe plate on the press roll.

The position of the tail anvil 31 relative to the lead or fixed anvil 29is controlled by a handwheel 37 and lead screw 39. The lead screw 39 isjournaled near each end in bushings 41 and has a tail anvil adjustmentcarriage 47 which can travel along the lead screw. A rod 45 is attachedto the tail anvil and passes through the tail anvil adjustment carriage.The rod 45 can be driven horizontally by the lead screw 39 and is freeto move vertically through the carriage 47 when the movable bed 19 isdriven upwardly by the ram 21.

As in the case of the supporting frame for the bender, the movable bed19 and the anvils 29 and 31 are of heavy steel construction to precludedistortion in bending the printing plate. The bed 19 is approximately 1inch thick while the anvils are approximately 1 1% inches thick. Sincethe anvils are -quite large and heavy, refer to FIG. 4, the fixed anvil29 is broken into several smaller segments 30 of the same configuration.Breaking up the large anvil 29 in this manner substantially reduces theweight which must be lifted by the ram.

The working faces of the anvils 29 and 31 are preferably formed atdifferent angles. The working face 33 of the anvil 29 forms the leadingedge of the printing plate and is preferably cut at an angle of 45. Theworking face 35 of the adjustable or tail anvil 31 is preferably cut atan angle of 60. As previously discussed, the tail angle is not as sharpas the leading edge angle since this portion of the plate is drawn intothe cutout in the press roll in tightening the plate and it isundesirable to form a sharp edge since this may produce a print lineduring use of the plate.

Spaced approximately 3 inches above each of the anvils are pressureblock assemblies 49 and 51. The pressure block assembly 49 is fixed inposition relative to the fixed anvil 29 and cooperates with the anvil inshaping the leading edge of the printing plate. The pressure blockassembly 51 is adjustable relative to the anvil 31 and cooperates withthe anvil 31 in forming the tail edge of the printing plate. Thepressure block assemblies like their cooperating anvils extendcompletely across the movable bed l9.

The fixed pressure block assembly 49 is supported from the top plate 17by a pair of supporting brackets 53 and 55. The assembly is made up offour major elements, a pressure block or gripping foot 57, a pair ofidentical camming plates 59, and a fonning block 61. The camming plates59 are mounted outside of the forming block and have camming slots 63 inwhich cam followers 65, which are mounted on each end of the formingblock, travel. The pressure block 57 and camming plates 59 can be drivenupwardly when the anvil 29 is raised by the pneumatic ram 21. As theseelements move upwardly, the camming slots 63 draw the cam followers 65inwardly, causing forming block 61 to come into contact with the workingface 33 on the anvil 29. The pressure block 57 is guided vertically by apair of similar guide posts 67 which are journaled in bushings 69 in thetop plate 17. Coil springs 71 surround each of the guide posts 67 andapply the gripping force against a lithographic plate supported on theanvil 29. The forming block 61 is prevented from rising by the shafts 73which are journaled through bushings 75 in the supports 53 and 55.

The camming block assembly 51 is adjustable to cooperate with the anvil31 in forming the bend for the tail edge of the plate. The assembly hasa pressure block or gripping foot 77, a pair of identical camming plates79, and a forming block 81. The camming plates 79 are mounted outside ofthe forming blocks and have camming slots 83 in which cam followers 85on the forming block 81 travel. The foot 77 is guided vertically by apair of similar guide posts 87 which pass through similar bushings 89 inthe top plate 17. Coil springs 91 about each post 87 provide a grippingforce for the foot 77 against a printing plate supported by the tailanvil 31. It also provides a force for returning the pressure blockassembly to its downward position after the movable bed 19 is lowered.

As previously indicated, the pressure block assembly 51 is adjustable tocooperate with the tail anvil 31. To provide for adjustment, theassembly 51 is supported by a plate 93 which can be moved across thesurface of the top plate 17. In order to provide for rapid adjustment ofthe assembly 51 into predetermined positions T pins 95 can be passedthrough apertures 97 in the plate 93 and into recesses 99 in the plate17. The bushings 89 are supported by the plate 93 and pass throughelongated slots in the top plate 17. An additional plate 100 issupported below the top plate 17 and can be drawn upward by hendwheels102 to tighten the assembly to the top plate 17 after it has beenadjusted into position.

The gripping foot 77 and camming plates 79 are pushed upwardly by thetail anvil 31 when the movable bed 19 rises. The forming block 81 isprevented from rising by the guide posts 101 which project throughbushings 103 in supports 105 which depend from the plate 93. As the foot77 tends to rise the camming plates 79 and camming slots 83 draw camfollowers 85 and forming block 81 inwardly against the working face 35on the anvil 31. When the movable bed 19 is lowered, the springs 91force the foot 77 downwardly and the camming slots again act on the camfollowers 85 to push the forming block 81 back to its starting position.The pressure blocks 57 and 77 and associated anvils 29 and 31 apply onlyenough pressure to the lithographic plate to hold it from moving duringthe bending operation. The pressure should not be so high that the plateis crushed or distorted.

in operating the lithoplate bender, the operator should place thelithographic plate onto the anvils 29 and 31, being careful to place thelocating pins 32 and 34 through the locating holes in the printingplate. A pair of operating valves 107 and 109 are then actuated by theoperator using palm buttons 111 and 113. Since the operator has toactuate two valves simultaneously, the operators hands will be occupiedand protected from inadvertent injury when the anvils and pressureblocks are compressed together. The operator must continue to press thepalm button until the movable bed 19 has caused the pressure blockassemblies to bring the forming blocks into engagement with the printingplate and the working faces 33 and 35 on the fixed and adjustableanvils. The movable bed 19 rises approximately 3 inches to reach thepressure blocks and then approximately 1% inch to 1 inch further tocomplete the bend. After the plate is completely bent, the operator mayrelease one or both palm buttons which will vent the pneumatic ram andcause the movable bed 19 to lower onto the support table 13. Theoperator can then slide the finished bent printing plate off the anvils29 and 31.

Referring to FIG. 5, a portion of a printing plate is shown resting onthe surface of the anvil 29 with the gripping foot 57 and forming block61 in their initial positions. After the operator initiates the machineaction, the anvil 29 rises, bringing the printing plate into contactwith the gripping foot 57 and the forming block 61. As the anvilcontinues to rise, the camming action draws the forming block inwardly,causing the plate to bend and to be shaped around the working face onthe anvil 29. When the bend is completed, the anvil lowers and springpressure on the gripping foot 57 causes the cam to push the formingblock 61 back to the initial position. When the anvil is at rest in itslower position, the operator can slide the bent lithographic plate offof the anvils.

While the operation has been described as completely under the controlof an operator, it is possible to improve the operation of the bender byplacing a limit switch 115, refer to FIG. 1, so that the switch iscontacted during the upward movement of the movable bed 19. The switchcan be adjusted so that it will trip when the plate is properly bent. Inthis type of operation the movable bed will rise, bringing the plateinto contact with the pressure block assemblies and will continue torise until the proper degree of bending is achieved. At this point, thelimit switch 115 will trip, stopping the upward movement of the movablebed and anvils and allowing them to return to their initial position.

If a limited number of sizes of lithographic plates are to be bent onthe machine, it is recommended that the corresponding positions on theframe be marked for the adjustable pressure block assembly and movableanvil and that means such as pins be used to hold the two adjustablemembers in position during operation. When it is necessary or desired tochange the size of the plate being bent, it is merely necessary to pullthe pins, move the adjustable members to the appropriate stop, andreplace the pins, fixing all of the parts in their proper orientation.

Referring to FIGS. 6 and 7, an adapter plate 117 is shown mounted on thefixed anvil 29. The adapter plate is used when it is necessary to bend aprinting plate smaller in size than the adjustment capabilities of thebender. The adapter plate can be attached to the anvil 29 by bolts orother suitable means. The adapter plate is approximately the samethickness as the anvil 29 and has substantially similar leading and tailedge plate working faces. In view of the thickness of the adapter plate,a collar 119 must be placed about the shaft 23 of the pneumatic ram 21to prevent the ram from rising too far and possibly damaging thepressure block assemblies 49 and 51.

In working with the adapter plate, the fixed pressure block assembly canbend the plate about one working face of the adapter while the movablepressure block assembly can be brought across the supporting plate 17 asufficient distance to cooperate with the other working face of theadapter plate. As previously mentioned, if a limited number of adapterplates are to be used, it is recommended that pins or other blockingmeans be provided for the movable pressure block assembly 51 in order toprovide for rapid and accurate adjustment of the assembly.

While the pneumatic ram has been shown with the bender of the presentinvention, it is obvious that other types of driving means can beemployed which will provide a similar action. For example, an electricmotor and a screw drive could be used to raise and lower the movable bed19, or even a hydraulic system. A pneumatic drive is recommended asmedium pressure air sources, approximately 80 pounds per square inch,are usually available in the plate preparation areas of a lithographicprinting shop. Also, in view of the solvents used to prepare theprinting plates and the resultant explosive vapors which are present, itis far safer to use a pneumatic drive than a similar electric motordrive. The driving means selected must have sufficient capacity to liftthe movable bed and to push it against the pressure blocks to providethe bending force. Obviously, larger than necessary driving means can beused to have ample reserve capacity.

While a particular embodiment of the invention has been shown, it willbe understood, of course, that it is not desired that the invention belimited thereto since modifications may be made, and it is, therefore,contemplated by the appended claims to cover any such modifications asfall within the true spirit and scope of the invention.

We claim:

1. A lithoplate bender comprising:

a supporting frame,

a pair of spaced biased pressure blocks mounted within said frame,

a movable table within said frame which is adapted to move toward saidpressure blocks,

a pair of spaced anvil means on said table, said anvil means beingadapted to move said pressure blocks when the table moves bringing saidanvils into engagement with said pressure blocks,

a forming block associated with each of said pressure blocks,

a driving means on each of said pressure blocks,

a driven means on each of said forming blocks which is adapted to movesaid forming block into engagement with the anvils on said table whensaid anvils move said pressure blocks, and

a driving means for said table.

2. A lithoplate bender as set forth in claim 1 wherein said pressureblocks are spring biased and are disposed near the top of saidsupporting frame.

3. A lithoplate bender as set forth in claim 1 wherein one of said pairof spaced biased pressure blocks is adjustable relative to the otherpressure block.

4. A lithoplate bender as set forth in claim 1 wherein one of said pairof spaced anvil means is adjustable relative to the other anvil means.

5. A lithoplate bender as set forth in claim 1 wherein said spaced anvilmeans have plate bend forming surfaces.

6. A lithoplate bender as set forth in claim 1 wherein one of said anvilmeans has a pair of spaced pins for locating a lithographic printingplate on said spaced anvils.

7. A lithoplate bender as set forth in claim 5 wherein one of saidspaced anvil means has approximately a 60 plate forming surface and theother anvil means has approximately a 45 plate forming surface.

8. A lithoplate bender as set forth in claim 1 wherein each of saidforming blocks is shaped to mate with the plate forming surface on thecooperating anvil means.

9. A lithoplate bender as set forth in claim 1 wherein said drivingmeans on each of said pressure blocks is a camming slot.

10. A lithoplate bender as set forth in claim 1 wherein said drivenmeans on each of said forming blocks is a cam follower located withinthe camming slot on each of said pressure blocks.

11. A lithoplate bender as set forth in claim 1 wherein movement of saidpressure blocks in a first direction results in movement of theassociated forming block in a second direction substantially normal tosaid first direction.

12. A lithoplate bender as set forth in claim 1 wherein one of saidanvil means produces a sharp bend in the printing plate to form analigning edge while the other of said anvil means produces a smooth bendto provide for tightening of the printing plate on the press roll.

13. A lithoplate bender as set forth in claim 1 wherein an adapter isprovided for mounting on one of said anvil means for bending smalllithoplates.

14. A lithoplate bender as set forth in claim 13 wherein said adapterhas a leading and a tail edge forming surface.

15. A lithoplate bender as set forth in claim 13 wherein said adapterhas an approximately 60 leading edge and an approximately 45 tail edgeforming surface.

16. A lithoplate bender as set forth in claim-13 wherein said adapterhas a pair of spaced pins for locating a small lithographic printingplate on said adapter.

17. A lithoplate bender as set forth in claim 1 wherein the lithoplatebender has a limit switch to release said driving means for loweringsaid table.

18. A lithoplate bender comprising:

a supporting frame,

a movable table mounted within said frame,

a pneumatic ram on said frame for moving said table,

a fixed anvil having a plate forming surface disposed on said movabletable,

an adjustable anvil having a plate forming surface disposed on saidtable and movable relative to the fixed anvil,

a spring biased pressure block movably supported by said frame forcooperating with said fixed anvil,

an adjustable spring biased pressure block movably sup ported by saidframe for cooperating with said adjustable anvil,

a pair of spaced camming slots on each of said pressure blocks,

a movable forming block associated with each of said pressure blocks,and

a pair of cam followers on each of said movable forming blocks which areguided within the camming slots on each pressure block,

said table being adapted to move bringing the anvils into engagementwith said pressure blocks, further movement of said table causing saidpressure blocks to move camming the forming blocks into engagement withthe forming surfaces on said anvils.

1. A lithoplate bender comprising: a supporting frame, a pair of spacedbiased pressure blocks mounted within said frame, a movable table withinsaid frame which is adapted to move toward said pressure blocks, a pairof spaced anvil means on said table, said anvil means being adapted tomove said pressure blocks when the table moves bringing said anvils intoengagement with said pressure blocks, a forming block associated witheach of said pressure blocks, a driving means on each of said pressureblocks, a driven means on each of said forming blocks which is adaptedto move said forming block into engagement with the anvils on said tablewhen said anvils move said pressure blocks, and a driving means for saidtable.
 2. A lithoplate bender as set forth in claim 1 wherein saidpressure blocks are spring biased and are disposed near the top of saidsupporting frame.
 3. A lithoplate bender as set forth in claim 1 whereinone of said pair of spaced biased pressure blocks is adjustable relativeto the other pressure block.
 4. A lithoplate bender as set forth inclaim 1 wherein one of said pair of spaced anvil means is adjustablerelative to the other anvil means.
 5. A lithoplate bender as set forthin claim 1 wherein said spaced anvil means have plate bend formingsurfaces.
 6. A lithoplate bender as set forth in claim 1 wherein one ofsaid anvil means has a pair of spaced pins for locating a lithographicprinting plate on said spaced anvils.
 7. A lithoplate bender as setforth in claim 5 wherein one of said spaced anvil means hasapproximately a 60* plate forming surface and the other anvil means hasapproximately a 45* plate forming surface.
 8. A lithoplate bender as setforth in claim 1 wherein each of said forming blocks is shaped to matewith the plate forming surface on the cooperating anvil means.
 9. Alithoplate bender as set forth in claim 1 wherein said driving means oneach of said pressure blocks is a camming slot.
 10. A lithoplate benderas set forth in claim 1 wherein said driven means on each of saidforming blocks is a cam follower located within the camming slot on eachof said pressure blocks.
 11. A lithoplate bender as set forth in claim 1wherein movement of said pressure blocks in a first direction results inmovement of the associated forming block in a second directionsubstantially normal to said first direction.
 12. A lithoplate bender asset forth in claim 1 wherein one of said anvil means produces a sharpbend in the printing plate to form an aligning edge while the other ofsaid anvil means produces a smooth bend to provide for tightening of theprinting plate on the press roll.
 13. A lithoplate bender as set forthin claim 1 wherein an adapter is provided for mounting on one of saidanvil means for bending small lithoplates.
 14. A lithoplate bender asset forth in claim 13 wherein said adapter has a leading and a tail edgeforming surface.
 15. A lithoplate bender as set forth in claim 13wherein said adapter has an approximately 60* leading edge and anapproximately 45* tail edge forming surface.
 16. A lithoplate bender asset forth in claim 13 wherein said adapter has a pair of spaced pins forlocating a small lithographic printing plate on said adapter.
 17. Alithoplate bender as set forth in claim 1 wherein the lithoplate benderhas a limit switch to release said driving means for lowering saidtable.
 18. A lithoplate bender comprising: a supporting frame, a movabletable mounted within said frame, a pneumatic ram on said frame formoving said table, a fixed anvil having a plate forming surface disposedon said movable table, an adjustable anvil having a plate formingsurface disposed on said table and movable relative to the fixed anvil,a spring biased pressure block movably supported by said frame forcooperating with said fixeD anvil, an adjustable spring biased pressureblock movably supported by said frame for cooperating with saidadjustable anvil, a pair of spaced camming slots on each of saidpressure blocks, a movable forming block associated with each of saidpressure blocks, and a pair of cam followers on each of said movableforming blocks which are guided within the camming slots on eachpressure block, said table being adapted to move bringing the anvilsinto engagement with said pressure blocks, further movement of saidtable causing said pressure blocks to move camming the forming blocksinto engagement with the forming surfaces on said anvils.